1. Field of the Invention
The present invention relates to an automatic programming apparatus which automatically generates an NC program for numerically controlling a machine tool, or more specifically an NC program for applying chamfering on the edges of machined faces of a semifinished workpiece obtained by machining a blank to be machined into a predetermined shape.
2. Description of the Prior Art
When a blank as a material to be machined is machined into a prescribed product shape by a machine tool, burrs may be generated on the edges of the machined faces. Such burrs not only can hurt a human operator if he accidentally touches them, but are also undesirable from the point of view of appearance of the product; therefore, the burrs are removed as needed by using, for example, a robot, and the blank is finished into the final product shape.
The robot is configured to operate in accordance with a pre-generated control program to deburr the edges of the machined faces of the product by chamfering (slight-chamfering) the edges by using a tool (grinder or the like) attached to its hand. In the prior art, such a control program is generated in the following manner.
First, the operator displays the product's CAD data generated by a CAD system on a CRT and selects a suitable geometric element (geometric line, etc.) from the displayed data by using a mouse or the like, to generate a tool path so that the chamfering will be applied to the portion corresponding to the selected geometric element; then, based on the thus generated tool path, the control program is generated (refer to Japanese Unexamined Patent Publication No. 5-165509).
However, the above method, which requires the operator to select and specify the portion of the product to be chamfered when generating the control program, not only has been inefficient, but also has had the problem that, due to the operator's error (human error), a portion that actually need not be chamfered may be selected and specified as the portion to be chamfered or, conversely, the portion that needs chamfering may not be selected and specified as the portion to be chamfered.
The present invention has been devised in view of the above situation, and an object of the invention is to provide an automatic programming apparatus that can accurately and efficiently generate an NC program for performing chamfering.